Big uproar over broken sidewalks
Who is going to fix your broken sidewalk? "The State of California Improvement Act of 1911" give cities the authority to require property owners to repair the sidewalks abutting their property (California Streets and Highways Code.) and the authority to make the repairs and assess the property owner for the cost should the property owner fail to make such repairs. There is an unless: Los Angeles Municipal Code (Section 62.104, Ordinance No. 146.040 effective July 3, 1974) exempts homeowners from the responsibility for sidewalk repairs caused by city owned trees and places responsibility for these repairs with the City's Department of Public Works. 
Okay, now that said at the rate the city is going if you call in a request for the city to repair your sidewalk today you probaly won't see a repair crew outside your house for about 50 years. Yes, they are really that far behind. City crews repair about 60 miles of sidewalk a year. The 50/50 program will move your request closer to the top of the list and your repair will (should) be done in concrete instead of asphalt but you have to cover 50% of the cost and that program moves pretty slow as well. Because of underfunding only about 40 miles of sidewalk repair is completed a year under the 50/50 program.
So this is just another big plan by the city that is going nowhere.
For more information on who is responsible for fixing broken sidewalks and who to call to have your sidewalk fixed if it was damaged by a city owned tree go the Special Projects FAQ website.